The General Clinical Research Center (GCRC) at the University of Virginia School of Medicine includes a group of experienced NIH-supported investigators working in areas related to peripheral and cardiac vascular biology. These investigators have pioneered the development of contrast-enhanced ultrasound during microbubble infusion for the clinical imaging of the microvasculature. As this area has developed through initial work in laboratory animals, it has increasingly become apparent that it is a valuable tool for clinical investigations. To efficiently support the clinical application of this evolving technology, the University of Virginia GCRC requests support for a Phillips HDI 5000 SonoCT Ultrasound System instrument for use by investigators with GCRC and human investigations committee approved protocols. Current efforts at implementing the full spectrum of microbubble applications to clinical investigations is hampered by the lack of an instrument dedicated to clinical research. Currently, undertaking these studies in our GCRC requires that ultrasound equipment be borrowed from our Heart Center Clinical Diagnostic Laboratories. This creates significant difficulties with lack of instrumentation being available during times when subjects are scheduled for research protocols. The instrument requested is a Phillips HDI 5000 Sono CT system with its associated multiple probes, software, and image analysis material. This instrument was selected as it meets the needs of multiple investigators for application to a variety of tissues and potential applications. It will provide important support for a total of 5 individual NIH RO-1, 2 K08, 1 K23 and 1 T32 supported research programs and to the overall mission of the GCRC which has been supported by a M01 grant for 30 years.